• 제목/요약/키워드: Magnetic Resonance Spectroscopy

검색결과 631건 처리시간 0.022초

Human in-vivo 31P MR Spectroscopy of Benign and Malignant Breast Tumors

  • Jeong Mi Park;Jae Hyung Park
    • Korean Journal of Radiology
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    • 제2권2호
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    • pp.80-86
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    • 2001
  • Objective: To assess the potential clinical utility of in-vivo 31P magnetic resonance spectroscopy (MRS) in patients with various malignant and benign breast lesions. Materials and Methods: Seventeen patients with untreated primary malignant breast lesions (group I), eight patients with untreated benign breast lesions (group II) and seven normal breasts (group III) were included in this study. In-vivo 31P MRS was performed using a 1.5 Tesla MR scanner. Because of the characteristics of the coil, the volume of the tumor had to exceed 12 cc (3×2×2 cm), with a superoinferior diameter at least 3 cm. Mean and standard deviations of each metabolite were calculated and metabolite ratios, such as PME/PCr, PDE/PCr, T-ATP/PCr and PCr/T-ATP were calculated and statistically analyzed. Results: Significant differences in PME were noted between groups I and III (p=0.0213), and between groups II and III (p=0.0213). The metabolite ratios which showed significant differences were PME/PCr (between groups II and III) (p=0.0201), PDE/PCr (between groups I and III, and between groups II and III) (p=0.0172), T-ATP/PCr (between groups II and III) (p=0.0287), and PCr/T-ATP (between groups II and III) (p=0.0287). There were no significant parameters between groups I and II. Conclusion: In-vivo 31P MRS is not helpful for establishing a differential diagnosis between benign and malignant breast lesions, at least with relatively large lesions greater than 3 cm in one or more dimensions.

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Combination of Magnetic Resonance Spectroscopy and 11C-Methionine Positron Emission Tomography for the Accurate Diagnosis of Non-Enhancing Supratentorial Glioma

  • Nijiati Kudulaiti;Tianming Qiu;Junfeng Lu;Huiwei Zhang;Zhengwei Zhang;Yihui Guan;Dongxiao Zhuang;Jinsong Wu
    • Korean Journal of Radiology
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    • 제20권6호
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    • pp.967-975
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    • 2019
  • Objective: To evaluate whether the combination of magnetic resonance spectroscopy (MRS) and 11C-methionine positron emission tomography (11C-MET PET) could increase accurate diagnostic sensitivity for non-enhancing supratentorial gliomas. Materials and Methods: Between February 2012 and December 2017, 109 patients with non-enhanced supratentorial lesions on contrast-enhanced MRI were enrolled. Each patient underwent MRS and 11C-MET PET before treatment. A lesion was considered to be a glioma when either the MRS or 11C-MET PET results reached the diagnostic threshold. The radiological diagnosis was compared with the pathological diagnosis or medical diagnostic criteria. Results: The sensitivity and specificity were 60.0% and 50.0% for MRS and 75.8% and 50.0% for 11C-MET PET, respectively. Upon combining the two modalities, the sensitivity and specificity of the imaging-based diagnosis prior to surgery reached 89.5% and 42.9%, respectively. Statistically significant differences in the sensitivities were observed between the combined and individual approaches (MRS alone, 89.5% vs. 60.0%, p < 0.001; 11C-MET PET alone, 89.5% vs. 75.8%, p = 0.001). However, no significant differences in specificity were observed between the combined and individual modalities. Conclusion: The combination of MRS and 11C-MET PET findings significantly increases accurate diagnostic sensitivity for non-enhancing supratentorial gliomas without significantly lowering the specificity. This finding suggests the potential of the combined MRS and 11C-MET PET approach in clinical applications.

Development of Superparamagnetic Iron Oxide Nanoparticles (SPIOs)-Embedded Chitosan Microspheres for Magnetic Resonance (MR)-Traceable Embolotherapy

  • Kang, Myung-Joo;Oh, Il-Young;Choi, Byung-Chul;Kwak, Byung-Kook;Lee, Jae-Hwi;Choi, Young-Wook
    • Biomolecules & Therapeutics
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    • 제17권1호
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    • pp.98-103
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    • 2009
  • Superparamagnetic iron oxide nanoparticles (SPIOs)-embedded chitosan microspheres were developed for magnetic resonance (MR)-traceable embolotherapy. SPIOs-loaded chitosan microspheres were prepared by emulsion and cross-linking technique and 100-200 ${\mu}m$ sized spherical microsparticles were obtained. Loading efficacy and loading amount of SPIOs in microspheres were about 40% and 0.26-0.32%, respectively, when measured by inductively coupled plasma atomic emission spectroscopy. Within 30 days, about 60% of the incorporated SPIOs were released from low cross-linked microspheres, whereas only about 40% of SPIOs was released from highly cross-linked microspheres. Highly cross-linked microspheres were more efficient for lower degree of swelling leading to secure entrapment of SPIOs in matrix. Prepared novel embolic microspheres are expected to be practically applicable for traceable embolotherapy with high resolution and sensitivity through magnetic resonance imaging (MRI).

Neurometabolic Improvement in Parkinson's Disease after Stereotactic Functional Neurosurgery by Follow-up MR Spectroscopy

  • Choe, Bo-Young;Baik, Hyeon-Man;Jeun, Sin-Soo;Son, Byung-Chul;Kim, Moon-Chan;Kim, Bum-Soo;Lee, Jae-Moon;Lee, Hyoung-Koo;Suh, Tae-Suk
    • 한국자기공명학회논문지
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    • 제7권1호
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    • pp.1-15
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    • 2003
  • PURPOSE - To investigate neurometabolism from the brain destructive lesions and striatal putamen-pallidus regions to the clinically worst side in patients with Parkinson's disease after stereotactic functional neurosurgery. METHODS - Using proton magnetic resonance spectroscopy ($^1$H MRS), fifteen patients (7 males and 8 females; mean age 56.5 years; age range 43-67 years) with Parkinson's disease (PD) were studied to measure N-acetylaspartate (NAA), creatine (Cr), choline-containing compounds (Cho) and lactate (Lac) levels on the neurosurgical lesions of thalamus, globus pallidus and striatal putamen-pallidus regions in a brain. RESULTS - Brain destructive lesion and striatal putamen-pallidus region in PD compared with controls were highly and significantly related to NAA/Cho ratios reduction, respectively (P =0.002, P =0.04), but showed no difference from the same regions of PD prior to neurosergery (P =0.06, P =0.77). Increased lactate peaks at 1.3 ppm were present in all the cerebral lesions, and these resonances were confirmed at a long TE =136 ms, indicating that these signals distinguished from lipids. CONCLUSIONS - Our results suggest that NAA/Cho ratios may provide as a neurometabolite marker for neurochemical changes in brain surgical lesion, and the ratios might be related to functional change of neuropathophysiological status in the striatal putamen-pallidus region of PD. Increase of lactate signals, being remarkable in surgical lesions, could be consistent with a common consequence of surgical necrosis. Therefore, MR spectroscopy could be a sensitive diagnostic tool in monitoring neurometabolic changes in PD with neurosurgical treatment.

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NMR methods for structural analysis of RNA: a Review

  • Kim, Nak-Kyoon;Nam, Yun-Sik;Lee, Kang-Bong
    • 한국자기공명학회논문지
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    • 제18권1호
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    • pp.5-9
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    • 2014
  • In last three decades, RNA molecules have been revealed to play the central roles in many cellular processes. Structural understanding of RNA molecules is essential to interpret their functions, and many biophysical techniques have been adopted for this purpose. NMR spectroscopy is a powerful tool to study structures and dynamics of RNA molecules, and it has been further applied to study tertiary interactions between RNA molecules, RNA-protein, and RNA-small molecules. This short article accounts for the general methods for NMR sample preparations, and also partially covers the resonance assignments of structured RNA molecules.

$^{11}B$ Quadrupole Interaction Studies of Boron-doped Graphite Electrode for Lithium Secondary Battery

  • Lee, Youngil;Han, Duk-Young;Lee, Donghoon;Woo, Ae-Ja;Lee, Sam-Hyeon;Kim, Kyung-Han;Lee, Man-Ho
    • 한국자기공명학회논문지
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    • 제3권2호
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    • pp.90-99
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    • 1999
  • Doping of boron atoms in graphite has been well known method to increase the discharge capacity as the negative electrode material for lithium secondary battery. Herein, the boron-doped graphites are prepared by mixing 1, 2.5, 5, and 7 wt. % of boron carbide in carbon during the graphitizing process. The structural states of boron in boron-doped graphites are investigated by solid-state 11B NMR spectroscopy. The resonance lines for substitutional boron atoms are identified as the second order quadrupolar powder pattern with the quardrupole coupling constant, QCC = 3.36(2) MHz. The quantitative analysis of 11B NMR spectra with boron-doped graphite has also been performed via simulation.

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1H, 15N, and 13C backbone assignments and secondary structure of the cytoplasmic domain A of mannitol trasporter IIMannitol from Thermoanaerobacter Tencongensis phosphotransferase system

  • Lee, Ko-On;Suh, Jeong-Yong
    • 한국자기공명학회논문지
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    • 제19권1호
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    • pp.42-48
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    • 2015
  • The mannitol transporter Enzyme $II^{Mtl}$ of the bacterial phosphotransferase system has two cytoplasmic phosphoryl transfer domains $IIA^{Mtl}$ and $IIB^{Mtl}$. The two domains are linked by a flexible peptide linker in mesophilic bacterial strains, whereas they are expressed as separated domains in thermophilic strains. Here, we carried out backbone assignment of $IIA^{Mtl}$ from thermophilic Thermoanaerobacter Tencongensis using a suite of heteronuclear triple resonance NMR spectroscopy. We have completed 94% of the backbone assignment, and obtained secondary structural information based on torsion angles derived from the chemical shifts. $IIA^{Mtl}$ of Thermoanaerobacter Tencongensis is predicted to have six ${\beta}$ strands and six ${\alpha}$ helices, which is analogous to $IIA^{Mtl}$ of Escherichia coli.

Mechanisms of Cu(II) Sorption at Several Mineral/Water Interfaces: An EPR Study

  • Cho, Young-Hwan;Hyun, Sung-Pil;Pilsoo Hahn
    • 한국자기공명학회:학술대회논문집
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    • 한국자기공명학회 2002년도 International Symposium on Magnetic Resonance
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    • pp.72-72
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    • 2002
  • In most traditional sorption study in environmental conditions, experimental sorption data have been measured and interpreted by empirical ways such as partition coefficient and sorption isotherms. A mechanistic understanding of heavy metal interactions with various minerals (metal oxides, clay minerals) in aqueous medium is required to describe the behavior of radioactive metal ions in the environment. Various spectroscopic methods provide direct or indirect information on sorption mechanisms involved. We applied EPR (Electron Paramagnetic Resonance) spectroscopy to investigate the nature of metal ion sorption at water/mineral interfaces using Cu(II) as a spin probe. The major sorbed species and their motional state was identified by their EPR spectra. They showed distinct signals due to their strength of binding, local structure and motional state. The EPR results together with macroscopic sorption data show that sorption involved at least three different mechanisms depending on chemical environments (1).

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Study on Magnetic Behavior of Zn1-xMnxO Films Grown on Si and α-Al2O3 Substrates by Sol-gel Method and Powders

  • Kim, Young-Mi;Park, Il-Woo
    • 한국자기공명학회논문지
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    • 제12권1호
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    • pp.26-32
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    • 2008
  • We report on the ferromagnetic characteristics of $Zn_{1-x}Mn_xO$ films (x = 0.3) prepared by sol-gel method on the silicon and (0001) ${\alpha}-Al_2O_3$ substrates at the annealing temperature of 700$^{\circ}C$. Magnetic measurements show that Curie temperature ($T_C$) and the coercive field ($H_C$) for the film on the silicon are about 32 K and about 275 Oe, while those for that on the sapphire are about 32 K and 425 Oe, respectively. Energy dispersive spectroscopy and transmission electron microscopy measurements suggest that ferromagnetic precipitates originated by manganese oxide compound formed at the interfaces of the both substrates may be responsible for the observed ferromagnetic behavior of the films. Electron paramagnetic resonance study of the powders up to the concentration of x=0.15 supports the result.

1D Proton NMR Spectroscopic Determination of Ethanol and Ethyl Glucuronide in Human Urine

  • Kim, Siwon;Lee, Minji;Yoon, Dahye;Lee, Dong-Kye;Choi, Hye-Jin;Kim, Suhkmann
    • Bulletin of the Korean Chemical Society
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    • 제34권8호
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    • pp.2413-2418
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    • 2013
  • Forensic and legal medicine require reliable data to indicate excessive alcohol consumption. Ethanol is oxidatively metabolized to acetate by alcohol dehydrogenase and non-oxidatively metabolized to ethyl glucuronide (EtG), ethyl sulfate (EtS), phosphatidylethanol, or fatty acid ethyl esters (FAEE). Oxidative metabolism is too rapid to provide biomarkers for the detection of ethanol ingestion. However, the non-oxidative metabolite EtG is a useful biomarker because it is stable, non-volatile, water soluble, highly sensitive, and is detected in body fluid, hair, and tissues. EtG analysis methods such as mass spectroscopy, chromatography, or enzyme-linked immunosorbent assay techniques are currently in use. We suggest that nuclear magnetic resonance (NMR) spectroscopy could be used to monitor ethanol intake. As with current conventional methods, NMR spectroscopy doesn't require complicated pretreatments or sample separation. This method has the advantages of short acquisition time, simple sample preparation, reproducibility, and accuracy. In addition, all proton-containing compounds can be detected. In this study, we performed $^1H$ NMR analyses of urine to monitor the ethanol and EtG. Urinary samples were collected over time from 5 male volunteers. We confirmed that ethanol and EtG signals could be detected with NMR spectroscopy. Ethanol signals increased immediately upon alcohol intake, but decreased sharply over time. In contrast, EtG signal increased and reached a maximum about 9 h later, after which the EtG signal decreased gradually and remained detectable after 20-25 h. Based on these results, we suggest that $^1H$ NMR spectroscopy may be used to identify ethanol non-oxidative metabolites without the need for sample pretreatment.